Color illumination



Oct. 17, 1944.

M.VA. MILLS COLOR ILLUMINATION Filed Jan. 22

R5. m w M MMM n p. WWW ""hllhl'llfllhhua w Patented Oct. 17, 1944 UNITEDSTATES PATENT OFFICE l Claim.

This invention relates to illuminated signs and, more particularly, tosigns empleying illumination in changing colors.

Although signs have been made and used employing illumination inchanging colors by the use of various combinations of colors, theproblem of satisfactorily combining these colors to obtain a uniformdistribution of the various colors produced by the combinations requiresspecial equipment and sometimes precludes the use of changing color.

It is, therefore, a primary object of the pres- The above and otherobjects of the invention 4 will appear more fully from the followingdetailed description, and by reference to the accompanying drawingforming a part hereof and wherem:

Fig. 1 is a perspective view of a sign constructed in accordance withthe principles of the invention herein disclosed.

Fig. 2 is a plan view partly in section and partially diagrammatic takensubstantially on line 2-2 of Fg. 1.

Fig. 3 is a Vertical cross section takenlsubstantially on line 3-3 ofFig. 1.

Fig. 4 is a modified form of structure for fastening the ends of thesign.

Referring to the drawing the numerals Ill, and |2 designate lamp socketsof the thermal flasher type mounted on a base |3 in substantialalignment as shown in plan view in Fig. 2. The base 13 is formed with'asubstantially straight front edge |3iand a curved rear edge |3b. A frontpanel |4 is secured to the front edge |3EV with a series of cut-outletters, or other characters 15 desired to be displayed, mounted at thetop of the panel |4. A rear panel IB is secured to the rear curved edgeI?b of the base and extends upward preferably a distanc'e above the topof the characters 15 on the panel I 4. The rear panel IB is thus formedin a curve in plan view as shown in Fig. 2 but with the panel formedstraight in Vertical section as shown in Fig. 3. The ends of the panels|4 and 16 nearly meet at the ends ofthe sign and are preferably securedin slots ll, l8 and 19, 20 of Vertical end pillars 2| and 22.

An important part of the combination is the provision of a refiectingand light blending surface 25 on the inside of the curved rear panel 16.This surface 25 may be described as employing a reflecting and lightblending surface by provision of embossed, multiple faceted, raised,criss-crossing, wrinkled or pebbled formations on the said reflectingand light blending surface. The surface 25 extends above panel |4 andbebind the cut-out or silhouette characters [5.

VThe three' lamp sockets IO, l and l2 carry light sources preferably ofred, blue and green lamps respectively as marked on the perspective viewFig. 1. The front panel |4 is of such height as to extend slightly abovethe lamps and the curved rear panel |6 with its blending surface 25 isshown extending well above the characters l5, thus forming a background.

The lamp sockets IO, I and l2, as previously noted, are of the thermalflasher type and may be purchased commercially. The general structure ofsuch a socket, however, is shown diagrammatically in Fig, 2 where thethree sockets IO, ll and |2 are shown connected in parallel from 'asource of electric current brought in by suitable wiring 26 thru theback panel. In each socket there is a bi-metallic element 28 having awinding of resistance wire for heating the element. The element 28 issupported at one end and normally closes contacts 29 at its oppositeend. However, when the current is on the element is heated and thedefiection of the element caused by the heat breaks the contact 29. Whenthe element cools sufiiciently the contacts 29 again come together. Theflasher unit being in series with the lamp filament as shown, the resultis a constant making and breaking of the circuit fiashing the lamp onand off at intervals depending upon the time required to heat and coolthe thermal element.

With thermal fiasher units in each of the sockets IO, ll and |'2controlling the fiashing on and off, the three lamps having such colorsas for instance red, blue .and green respectively there results ahaphazard combination of these colors as the flashers are not entirelyuniform in their timing when operated continuously. The result is thatone lamp 'may be lighted alone at one time, any combination of two, orall three, and if the light is properly diffused and mixed the resultresults in blending the colors in a satisfactory manner thus to attainthe desired result of blending the various combinations of primarycolors. Also by using a light blending surface in combination with acurved back, a uniform distribution of light is obtained even when oneof the end lamps is Operating alone. For the purpose of making the signcharacters easily readable this uniform distribution of light isessential. A fiat background with smooth reflector would reflect eachcolor back of its respective lamp and would produce little uniformity ofblending and furthermore would produce poor distribution of light whenindividual lamps are lighted alone, particularly the end lamps. Thepleasing result produced by the surface 25 curved in plan view,

in combination With the light sources in a substantial line, hasresulted after experiment with various arrangements and is consideredadvantageous, particularly since it produces desired results of colorblending with equipment of relative simplicity and commerciallypractical of use.

Some Variation in arrangement is possible while maintaining theprinciples above outlined and Fig. 4 shows a modified structure where acurved back panel 30 is formed at 3| into an end pillar and has a frontpanel 32 secured thereto. In this case the panels are preferablyconstructed of sheet metal. Either cardboard or metal may be employed inthe form shown in Figs. 1, 2 and 3.

A form of embossed or pebbled bright metal coated paper readily obtainedcommercially has been satisfactory as the material for the surface 25although other materials may be used which will produce like resultssuch as reflecting surfaces With embossed, criss-crossing, faceted,raised, wrinkled, pebbled or like surface. In order that there may be nomisunderstanding of terms used in the claims in this regard the termlight blending surface is selected for defining a surface of the generaltype herein described as distinguished from a surface which wouldreflect only, without blending.

In mentioning modifications which may be used and still maintain thefundamental principle I do not ntend that departure shall be made fromthe combination of light blending surface With the curved back panelwhich I have found essential to satisfactory results.

I claim: i

In a sign of the character described having sign characters to beilluminated, a plurality of intermittent and irregularly fiashing lightsources of different colors, spaced apart in substantial alignment, 'afront panel of height to cover the space in front of said light sourcesand adapted to support said characters to be illuminated above saidpanel, a back panel higher than said front panel and curved in plan viewand extending back of and above said light sources, a light blendingsurface on said curved back panel forming a background for blending saidlight combinations, producing a blending and uniform distributon ofchanging colored light when said light sources are lighted singly or incombnation.

MAURICE A. MILIS.

